Our layout algorithm was loosely based on the dag algorithm
proposed by Gasner, et al. [8]. However, we
used only their concepts of virtual nodes and rank (level)
assignment. Using only these two simple concepts, we were able to
quickly implement an algorithm that produced a relatively visually
acceptable graph. We realize, however, that a better algorithm will
be necessary to represent the graphs of larger systems. Work is
currently underway in this area.